# How do you calculate the ripple voltage of a power supply?

## How do you calculate the ripple voltage of a power supply?

Ripple current peak-to-peak into the −5V output capacitor is approximately equal to twice the negative load current. The wave shape is roughly rectangular, and so is the resultant output ripple voltage. A 100mA negative load and 0.1Ω ESR output capacitor will have (2)(0.1A)(0.1Ω) = 20mVP–P ripple.

### What is acceptable ripple on a DC power supply?

about 100mV peak

Acceptable ripple voltage is about 100mV peak to peak. Majority of good power supplies have ripple and noise figures of better than 10mV rms, while SMPS figures of 50mV or less are possible, however, higher current supplies are likely to have slightly higher values.

**Which type of instrument is used for measuring the DC ripple voltage?**

A ripple voltage is a small AC voltage, which is placed on top of a DC offset. It can be measured using a digital multimeter.

**How do you test a ripple with a multimeter?**

Select the “AC Voltage” by turning the dial on the front to the picture of an oscillatory wave. Bring the probes into contact with the circuit that has the ripple voltage. The multimeter will only measure the AC component of the signal — i.e., the ripple voltage.

## How do you calculate current ripple?

Current Ripple Measurement On A Cap By using the equation P = I2 × R, we find that 25W (7.0712 × 0.5Ω) of power has to be dissipated, so the bulk cap will get very hot after a while.

### How do I test a power supply ripple?

Select the “AC voltage” mode by turning the tester knob. The meter will only measure the AC component of the signal, the ripple voltage, if present. The display shows the measured value of the ripple voltage amplitude. If it shows the value 0.00 mV it means that, most likely, the ripple is absent.

**How do you test ac ripple voltage?**

Ripple voltage or (AC voltage) can be measured by switching your digital multimeter to AC and connecting the black lead to a good ground and the red lead to the “BAT” terminal on the back of the alternator, (not at the battery). A good alternator should measure less than . 5 V AC with the engine running.